Brush-holder for dynamo-electric machines.



M. WALKER.

BRUSH HOLDER FOR DYNAMO ELECTRIC MACHINES.

APPLICATION FILED MAR. 23, 1908.

909,834. Patented Jan.12,1909.

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L LT INVENTOR WITNESSES:

ATThRNEY UNITED srn'rns PATENT orsron.

MILES WALKER, OF HALE, ENGLAND, ASSIGNOR, BY MESNE ASSIGNMENTS, TO WESTING HOUSE ELECTRIC & MANUFACTURING COMPANY, OF EAST PITTSBURG, PENNSYLVANIA,

A CORPORATION OF PENNSYLVANIA.

BRUSH-HOLDER FOR DYNAMO-ELECTBIC MACHINES.

Application filed March 23, 1908.

Specification of Letters Patent.

To all whom it may concern:

Be it known that 1, MILES, \VALKER, a subject of the King of Great Britain, and a resident of Hale, in the county of Chester, England, have invented a new and useful Improvement in Brush-Holders for DynamoElectric Machines, of which the following is a specification.

This invention relates to brush holders for dynamo-electric machines, and has for its object to provide an improved brush holder which shall be especially adapted for use with dynamo-electric machines having grooved or corrugated commutators or collectors. In machines of this kind wherein the rubbing contact is made upon the two radial faces of the groove in the commutator or collector, the engaging contact blocks or brushes require to be so supported within the groove as to firmly resist a tendency to tangential movement by reason of the rotation of the commutator, and so as to effect a firm and even pressure on the contact surfaces.

According to the present invention, a brush holder is provided that comprises a frame or base plate having guides at one end in which two sets of brush blocks, of carbon or other suitable material, can slide freely in a direction at right angles to the length of the frame. The brush holder is so supported that the end carrying the guides for the brushes lies in the groove of the commutator, the axis of the frame being approximately normal to the cylindrical surface of the commutator, in such a manner that the base of the frame supports the brushes against the tendency to tangential movement.

My invention is illustrated in the accom panying drawings, in which Figures 1 and 2 are side and front elevations of a brush holder constructed in accordance therewith.

Referring to the drawings, the device here illustrated comprises a frame or base plate 1 having guide projections 2 and 3 which form a lateral recess l in which brushes or contact blocks 5 and 6, of carbon or other suitable material, are movably mounted. The guide projections 2 and 3 may be integral with the frame or base plate lor may be formed of sheet metal punchings that are secured to the frame by any suitable means.

The guide projection 3 is at one end of the frame 1 and is integral therewith, and the guide projection 2 which cooperates with it is adjustably secured to the frame, screws 7 being provided to engage slots 8 in the punching of which it is constructed in order that this result may be accomplished.

The end of the frame 1 which carries the guide project-ions is adapted to extend into a groove or corrugation 8 in a commutator or collector of a dynamo-electric machine and the brush blocks 5 and 6 are adapted to engage radial surfaces thereof. An adequate pressure is produced between the blocks and the surfaces which they engage by means of a V-shaped spring 9 which is secured to the outer extremity of the frame 1 by means of a screw 10 that engages a loop 11 formed at the point of the V. The arms of the spring extend from the loop 11 through a slot 12 in the guide projection 2 and engage the adjacent surfaces of the brush blocks.

The pressure exerted by the spring 9 may be varied by an adjusting screw 13, the said screw being threaded through a block lt with which one arm of the spring is provided, and being pressed against the inner surface of the other arm, thereby regulating the distance between the arms.

The brush blocks are preferably connected electrically to the frame or base plate 1 by means of flexible braided or strand conductors lat and 15 provided with terminals 16 that are clamped to the frame by means of screws 17.

It is conceivable that various modifications in the structure of the brush holder may be eflected within the spirit and scope of my invention, and I desire that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. A brush holder comprising a frame or base plate having guide projections that produce a lateral recess near one extremity, brush blocks movably mounted in the recess, and means for exerting a separating spring pressure against the brush blocks.

2. A brush holder comprising a frame or base plate having relatively adjustable guide projections that produce a lateral recess at one end of the frame, brush blocks movably mounted in-the recess, and a V-shaped spring having resilient arms that engage the adjacent surfaces of the blocks.

3. A brush holder comprising a frame or base plate of conducting material having guide projections that produce a lateral recess, one of said projections being adjustably attached to the frame, brush blocks movably mounted in the recess and electrically connected to the frame, and a V- shaped spring secured to the frame and having resilient arms which engage the adjacent surfaces of the contact blocks.

4:. A brush holder for electrical machines comprising a base plate or frame, two guide projections one of which is adjustable, brush blocks movably seated between said projections, a V-shaped spring having its apex fastened to the frame and the ends of its arms in engagement with the adjacent sides 20 of the brush blocks, and means for varying the distance between the arms to modify the pressure exerted against the brush blocks.

In testimony whereof, I have hereunto subscribed my name this 29th day of Febru- 25 

